Coffee has traditionally been consumed primarily for its taste and aroma and the stimulating effect of caffeine. The two main commercially cultivated species are Coffea canephora (predominantly a form known as ‘robusta’) and Coffea arabica. 
Coffee and its Health Benefits
It is known that coffee is a complex mixture of many hundreds of compounds several of which are phenolic compounds, which, in combination, form a unique and pleasing aroma and taste desired by many consumers (WO 2006108578 A1). Furthermore, coffee is consumed not only for its desirable flavor but often for other reasons, such as to increase short-term mental alertness.
The positive health impact of coffee has been studied over many decades and, for a long time it has been known that certain of these coffee compounds are capable of providing benefits to the consumer, especially greater mental alertness through the ingestion of caffeine. However, it is less well known to consumers that certain coffee compounds are excellent anti-oxidants and that, weight for weight, coffee can potentially provide significantly more antioxidants to the consumer than, for example, a well-known source of antioxidants such as green tea.
Potential health benefits of coffee bean derived phytochemicals include prevention of several chronic and degenerative diseases, such as cancer, cardiovascular disorders, diabetes and Parkinson's disease and also management of obesity. Whatever the extracting agent, the beans may be extracted more than once to enhance the process and obtain greater yields of phenolic compounds.
Not only are green coffee beans a source of beneficial phenolic compounds, but unit weight per unit weight, green coffee beans produce more beneficial phenolic compounds, and in a more beneficial constituency than that obtained in the form of extracts from green tea.
Phenolic compounds are a large and diverse group of molecules, which includes many different families of aromatic secondary metabolites in plants. Phenolic compounds derived from green coffee beans, are known to be antioxidants and anti-tumor agents. The phenolic acids viz. chlorogenic acid, caffeic acid, para-coumaric acid and eugenol have been shown to exert cancer preventive activities in animal models.
Despite the presence of phenolic compounds in coffee beans, and their known beneficial properties, phenolic compounds are conventionally obtained as extracts from green tea. This appears to be because coffee bean roasting processes reduce phenolic content in coffee beans between 40% and 80%, and no one has heretofore considered obtaining phenolic compounds from green coffee beans. Analysis by the present inventors indicate that green coffee beans which initially contain 4% phenolic acids contain respectively, 2% phenolic acids when light roasted, 1% when medium roasted, and less than 0.5% when dark roasted. This clearly represents a significant loss of beneficial compounds through the roasting process.
Hence, it is of immense benefit to mankind to provide a new and therapeutic preparation in form of green coffee bean extract of present invention which has powerful anti-oxidant, anti-tumor and anti-obesity properties owing to significantly higher content (70-80%) of the bioactive compounds responsible for the therapeutic benefits viz. Chlorogenic acids. It will likewise be of benefit to provide such improved preparations and/or new and more prolific methods for obtaining or producing such preparations on a commercial level, including that from other sources rich in Chlorogenic acids, including roasted coffee beans.
Chlorogenic Acid Content in Coffee Beans
US 2002/0160067 A1 discloses that the total chlorogenic acid (different types of Chlorogenic acids are present in extracts and their combined concentration is referred to as total Chlorogenic content) content of green arabica beans is typically 6.9% and in robusta variety it is typically 10%. A number of different chlorogenic acids are present—5-caffeoylquinic acid is present in the largest amount. Dicaffeoyl and feruloyl quinnic acids are also present together with the 3 and 4-isomers of monocaffeoylquinic acid. Green coffee beans typically contain 1.3% diterpenes in arabica and 0.2% diterpenes in green robusta. The diterpenes are cafestol and kahweol. Various sterols and tocopherols are also present in the lipid part of green beans. Alkanoylated 5-hydroxytryptamines (the Japanese compound) in the wax on the outer surface of the green beans are present at 500-1000 mg/kg (or 0.5-1%). Trigonelline is present at 1.1% is arabica and 0.65% in robusta. Trigonelline is transformed somewhat into nicotinic acid. Apart from chlorogenic acids, the main acids present in significant quantities are quinic, malic, citric, lactic, pyruvic, succinic and glycolic.
Importance of Chlorogenic Acids in Coffee
Chlorogenic acid is the main phenolic acid in coffee and a very important anti-oxidant. Chlorogenic acids in coffee are mainly mono- and di-esters of quinic acid and phenolic groups (e.g. caffeic, ferulic, coumaric, methoxycinnamic) attached to different positions. They have important health benefits, as below:                i. Anti-Oxidant activity—Chlorogenic acids have been shown to have antioxidant activity in vitro (e.g. radical scavenging, LDL oxidation resistance, DNA damage protection)        ii. Anti-mutagenic effect—Significant anti-mutagenic effect of such acids has been shown in vivo on large intestine, liver and tongue in rats and hamsters.        iii. Anti-acid: Chlorogenic acids are also able to reduce systemic acid secretion in the stomach protecting the gastric mucosa against irritations possibly responsible for heartburn.        iv. Anti-Obesity: Scientific studies have shown that chlorogenic acid enriched instant coffee appears to have a significant effect on the absorption and utilization of glucose from the diet. This effect, if the coffee is used for an extended time, may result in reduced body mass and body fat when compared with the use of normal instant coffee. (J Int Med Res. 2007 November-December; 35 (6): 900-8). Various studies have suggested that chlorogenic acid slows absorption of fat from food intake and also activates metabolism of extra fat. A study on the anti-obesity effects of green coffee bean extract rich in chlorogenic acid was published in January 2012 in the Diabetes, Metabolic Syndrome and Obesity journal. The researchers followed a group of 16 adults who supplemented their diet with a special green coffee bean extract of chlorogenic acids at different dosages (either 700 or 1050 milligrams per day) for 12 weeks. All 16 adults were considered overweight, as demonstrated by a BMI of greater than 25 (a normal BMI is between 18.5 and 25). The subjects lost an average of almost 18 pounds—this was 10% of their overall body weight and 4.4% of their overall body fat.        v. Anti-hypertensive: Reduces high blood pressure and helps maintain blood pressure in normal range. (Zhao, Y.; Wang, J.; Ballevre, O.; Luo, H.; Zhang, W. (2011). “Antihypertensive effects and mechanisms of chlorogenic acids.” Hypertens Res. 35 (4): 370-4. doi:10.1038/hr.2011.195. PMID 22072103).        vi. Anti-diabetic: Help maintain blood glucose levels in the normal range. Chlorogenic acid has specifically been shown to inhibit an enzyme, glucose-6-phosphatase, that promotes the formation of glucose (sugar) in the liver. Hence, chlorogenic acid in coffee may be responsible, at least in part, for the reduced risk of glycemic disorders, like diabetes, with long-term coffee consumption.        
From the health and nutritional perspective, it is desirable that consumers should be able to benefit from the positive health aspects of coffee identified above and so it would be highly advantageous to maximize the amount of chlorogenic acids available in coffee products. In this context, the present invention has achieved a remarkable technical advantage of significantly improving the Chlorogenic acid content of green coffee bean extracts to 70-80% compared to only 20-50% present in existing extracts.
The method by elaborating and disclosing the specific mechanism by which such an increase has been made possible, has enhanced the applicability of the same in improving the Chlorogenic acid content of extracts from other sources.
US 2002/0160067 A1 discloses that chlorogenic acid is suspected to be beneficial in preventing cardiovascular disease, has chemopreventative effect on rat stomach cancer and inhibits methylazoxymethanol-induced large intestinal tumors in hamsters. In vivo assays show that one third of chlorogenic acid and almost all caffeic acid is absorbed in the small intestine of humans. This implies that part of the chlorogenic acid from foods will enter into the blood circulation, but most will reach the colon. Caffeic acid seems to be more bioavailable. (Olthof et al J Nutr 2001 January; 131 (1): 66-71). Coffee contains phenolic acids which are mainly esters of quinic acid with different amount of caffeyl groups attached to its different positions. Chlorogenic acid, which is the main phenolic acid in coffee, is able to protect the gastric mucosa against irritations, and, therefore, improves the digestibility of foods, beverages and medicaments. The improved digestibility is expressed through a much reduced systemic acid secretion (such as causes heartburn, etc.) which has been found to be directly dependent on an increased level of chlorogenic acid content in roasted coffee.
Loss of chlorogenic acids during coffee processing: Conventional coffee process methods, where all of the beans that contribute to an end product are roasted, are well known. The specific taste and aroma is to a great extent formed during roasting of the coffee beans. However, it has been found that the roasting process degrades a significant amount of the chlorogenic acids present prior to roasting. Nevertheless, the achievement of desirable “roasty” coffee flavor is of such importance to consumers, that it has hitherto been necessary to roast the beans to a significant degree with the knowledge that this will cause undesirable degradation of certain beneficial compounds. The natural chlorogenic acid content of green coffee can be reduced by as much as about 40 to 90% by weight during conventional roasting processes.
Therefore, it is highly desirable to provide a coffee product, which both retains a much higher level of chlorogenic acids than traditionally associated with roasted coffee but which nevertheless provides an acceptable and even more desirable roasted coffee flavor. Ideally, the coffee product should at least provide organoleptic properties desired by the consumer and/or avoid or minimize any undesirable organoleptic properties.
The present invention discloses a green coffee bean extract in which the concentration of chlorogenic acid (s) is significantly higher than that disclosed in commercially available samples or as disclosed in prior art processes (70-80% vs. 20-50%).
Extract of the present invention thus has considerable commercial importance in ‘fortifying’ either existing coffee preparations or food and drink, medicines, cosmetics, or the like, with high amounts of chlorogenic acids which are normally lost during the roasting process.
Green Coffee Beans—The term “green coffee bean” refers to either immature coffee beans or even mature coffee beans which have not been roasted. Nonvolatile and volatile compounds in green coffee beans, such as caffeine, deter many insects and animals from eating them. They also contribute to the flavor of the coffee bean when it is roasted. Nonvolatile nitrogenous compounds (including alkaloids, trigonelline, proteins and free amino acids) and carbohydrates are of major importance in producing the full aroma of roasted coffee and for its biological action. Green Coffee Beans are a rich source of chlorogenic acid and other phytochemicals which are associated with several beneficial health effects. A substantial portion of phytochemicals gets destroyed during heating and roasting of the coffee beans. Key compounds in the coffee beverage, produced from ground, roasted beans, are volatile constituents responsible for the unique aroma, the alkaloids caffeine and trigonelline, chlorogenic acids, the diterpenes cafestol and kahweal, and melanoidins, which are Millard reaction products.
Chlorogenic acid(s)—This is a trivial name used somewhat loosely in the literature to describe a range of phenolic acids found in plant materials. For example, in some literature references, 5-caffeoylquinic acid alone is referred to as “chlorogenic acid”. As used herein, however, the term chlorogenic acid is used to describe one or more of a family of esters that form between certain cis or Trans cinnamic acids and quinic acid.
For the purpose of the present invention, the term ‘chlorogenic acid’ refers to the sum total of 7 chlorogenic acid homologues viz. 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 3,4 dicaffeoylqunic acid (3,4-diCQA), 3,5-dicatffeoylquinic acid (3,5-diCQA). 4,5-dicaffeoylquinic acid (4,5-diCQA), 4-feruloylquinic acid (4-FQA) and 5-feruloylquinic acid (5-FQA). The chlorogenic acid isomers may be determined by HPLC with UV detection at 320 nm using 5-CQA as external standard to calculate the concentrations. The HPLC graph obtained on analysis of green coffee bean extract of present invention, showing seven distinct peaks is as depicted in FIG. 2.
Formula: C16H18O9; Molar mass: 354.31 g/mol and Density: 1.28 g/cm3 
Structure of the acid is given in FIG. 1.
Health Benefits of Chlorogenic Acid
Chlorogenic acid found in raw green coffee beans is associated with several health benefits which includes control of hypertension, blood glucose management and also weight loss. Though present in high concentrations in green coffee beans, chlorogenic acid is destroyed when the beans are ‘roasted’. Raw coffee beans are the most abundant natural plant source of chlorogenic acid. Green coffee bean extract in powder form, containing about 40-50% chlorogenic acid is generally consumed as a supplement (in form of capsules) since drinking liquid coffee made from unroasted coffee beans would have a bitter unpleasant taste and would not provide the desired dosage of chlorogenic acid.
Some recent research has suggested chlorogenic acid may improve retinal health. Other research suggests that chlorogenic acid inhibits the release of glucose into the blood stream. Japanese researchers did a study in 2005 using a placebo for some participants and green coffee bean extract on the others, in a test of the potential effects of the substance on people with mild hypertension. The result was lower blood pressure and no negative side effects. Currently a lot of studies are being conducted for using green coffee bean extracts as anti-obesity agents and treatment of life style-related diseases such as diabetes which may result due to obesity.
Dosage—The recommended dosage of Green Coffee Bean Extract as per recommendation of a commercial manufacturer (http://healthfoodpost.com/green-coffee-extract/green-cofee-bean-dosage/) is one capsule of 400 mg taken three times per day. The supplement should be taken 30 minutes before breakfast, lunch and dinner. The manufacturer warns that dosage is not to exceed (4) capsules (1600 mg) per day. Green Coffee Bean Extract contains 50% Cholorogenic Acid. Thus, the recommended safe daily dosage of Cholorogenic Acid is 600 mg (if taking 3 capsules of 400 mg each, containing 50% chlorogenic acid). The extract of present invention has higher content of Chlorogenic acids (70-80%) due to which number of capsules needed are less or for same number of capsules, better therapeutic benefits can be achieved by the consumers.
Concerns regarding presence of caffeine: Apart from Chlorogenic acids, the extract also contains trace amounts of caffeine. One capsule may contain approximately 8 mg of caffeine (3 capsules would thus contain about 24 mg of caffeine). A typical cup of regular coffee contains, on an average, 150 mg of caffeine. Some roasted coffees contain as much as 400 mg of caffeine per cup. Thus, the amount of caffeine in dietary capsules is much less than what is consumed directly as coffee drink and hence is not a cause of concern, unless a person is very sensitive to minimal amounts of caffeine.
The bioactive components in green coffee bean extract are thus ‘chlorogenic acids’ apart from other phytochemicals. Standardization of dietary supplements e.g. capsules is carried out in terms of content of the chlorogenic acid e.g. Green Coffee Bean extract containing 40% chlorogenic acid, 50% chlorogenic acid etc. Chlorogenic acid content of the extract thus has considerable therapeutic and commercial value.
Chlorogenic acid content of the present invention—The extract of present invention has significantly higher concentration of chlorogenic acid (almost double) than that of existing prior art or commercially available products, apart from presence of other useful phytochemicals which get destroyed during heating and roasting of the coffee beans but are present in the fraction of the invention since extraction is done without heating. The chlorogenic acid content of the fraction of present invention is about 70-80% vs. about 40-50% in commercially available fractions.
The extract of the present invention thus represents a unique product with considerably higher bioactivity in terms of anti-oxidant activity and also presence of valuable phytochemicals, which otherwise get destroyed when the green coffee beans are subjected to roasting and heating. The extract of invention is thus novel in terms of containing a significantly higher content of Chlorogenic acids (70-80%), not disclosed in prior art and elaborated for the first time in present invention along with the method for achieving the same. Further, the method of the present invention is applicable to extracts obtained from other natural source, including roasted coffee beans.